Buffing machine



force air through the Patented Jan. 17, 1928.

UNITED STATES 7 1,656,182 PATENT OFFICE.

v ERNST FREDERIK HENRY ENNA, OI COPENHAGEN, DENMARK.

I BUFFING MACHINE.

- Application filed latch 27, 1925, Serial No. 18,778, and in GreatBritain August 30, 1924.

- This invention relates to butting-machines,

more particularly for use in finishing the.

provided with an abrasive. cover, t e pad be ing maintained. in aninflated condition by means of a suitable air pump, adapted to spindleinto the pad to inflate the same. i

The object of the present invention is to provide a buffin -machinecharacterized as above stated, of simple construction and adapted tomaintain a charge of air within the inflatable pad for a considerabletime, without renewal.

To this end according to this invention, the pump for producing andmaintaining the pressure in the inflatable pad comprises a piston fixedto one'end of the spindle, and a cylinder slidable on the spindle andthe piston, the spindle having a longitudinal air duct, and thecylinder-being adapted to be reciprocated by hand so as to deliver airpast a non-return valve in the duct of the spindle and thence to theinterior of the pad. A relief valve is preferably provided at aconvenient point in the spindle, with its stem extending through thewall thereof, whereby the pressure may be relieved when desired.

Means for securing the pad aswell as its abrasive cover, to one end ofthe spindle,

conveniently comprises an annular seat rigidly mounted on the spindle,and an annular clamping member carried and adapted to be movedlongitudinally by a nut, having a screw-thread engagement with thespindle,

so as to clamp. an annular flange on the pad, together with the padcover, between the clamping member and the seat.

The accompanying drawing forming a partof this specification, showspartly in elevation and partly in section, a bufling machine embodyingthe invention, the main portion of the supporting frame being omitted.

In the drawings, A designates a frame member or portion, adapted to besecured to a main supporting frame (not shown), by

means of a rod 13. The member A is rovided with two bearings C and D wich preferably of rubber, adapted to back a cover of abrasive material.such as sandpaper, emer cloth or the like. The pad is provide with anannular flange F. This flange, and the margin of the abrasive cover areconfined by attaching means includingan annular seat G, fixed to thespindle, and a longitudinally movable clamping member H.

The clamping member H is movable into and out of its clamping positionby means of a nut H, having a groove therein engaged by a flange H atthe upper end of the tubular shank H of the clamping member. To theupper end of the spindle is fixed a piston of the cup leather type. Jdesignates a cylinder which is slidable on the spindle and piston. Thecylinder J is provided with an vair inlet J,'below the piston K and canbe reciprocated b hand, so as to force air through the duct into the padF, a non-return valve L being provided in the duct to prevent the returnof air to the cylinder. The valve L may be of the type usually employedin pneumatic tires, and yields or opens when the cylinder is projectedtoward the pad, and closes when the cylinder is retracted.

A spring M is provided serving to yieldingly arrest the upward movementor retraction of the cylinder J. The spindle is provided with an airvent between its ends, and with a spring-pressed relief valve N, thestem of which projects from the spindle and is manually movable to openthe air vent and permit the escape of air to reduce the pressure in thepad.

In machines of this type it is usual to provide aduct for conveying awaythe dust produced by the bufling. In order that the spindle E may beadjusted so as to bring the pad F adjacent the mouth of such duct, therod B is adapted to be clamped to its support at any point in itslength.

The vertical position of the pulley E with reference to the bearingmembers C and D can be varied, as for example, by reversing the sleeveon which the pulley is mounted.

The details of construction may be varied without departing from thesplrit of the invention as defined by the following claims.

I claim:

1. In a bufling machine, the combination of a tubular rotatable spindle,an inflatable pad secured to one end of the spindle and communicatingwith the bore thereof, a piston secured to the other end of the spindleand provided with a continuation of the spindle bore, a manually movablepump cylinder into which the piston and adjacent end of the spindleextend, said cylinder be- ,ing adapted to be reciprocated over thepiston and spindle in the direction of the len h of the spindle, anon-return valve wit in the air duct adjacent the piston, the" andhaving a section of its body adjacent said flange exteriorly threaded,an inflatable I the end of the spin pad having a portion of its casingextending inward over said flange on the spindle, an annular clampingmember surrounding the spindle and having one end ada ted to clamp thepad casirg againstthe ange at e and its opposite end provided with aflan e, a nut engaging the threaded section of t e spindle,,and havingan interior groove engaging the flange on the clampin member whereby theclamping member wil be positively moved both to-i ward and from the padas the nut is rotated,

and means communicating with the interior of the spindle for forcing airinto the pad to inflate the latter.

In testimony whereof have affixed my signature.

ERNST FREDERIK HENRY ENNA.

